The Slovak pocket rocket, who stands just 1.61 meters (5 feet, three inches), played a big match to impose her game on Petrova, who was attended by the trainer after losing the draining, 63-minute opening set.

She then stormed through the second set, wrapping up the victory in just over 90 minutes.

Cibulkova, who reached her first final since the clay court tournament in Barcelona in April, next faces either French top seed Marion Bartoli or Taiwanese qualifier Chan Yung-jan.

Bartoli went into their evening semi-final after struggling in her last two matches -- both three-setters -- and has been dealing with a leg injury.

Cibulkova has now won three of four meetings with Petrova, who was seeded fourth.

The Slovak player recovered from an early break to force the first-set tiebreaker with a break in the 12th game.

Petrova raced to a 4-0 lead in the decider, but she was slowly pegged back by her persistent opponent.

Cibulkova, thriving as Petrova faded, saved a set point and finally sealed the set on her third opportunity when Petrova sent a tired backhand out.